Sawmill log turner



Aug. 9, 1960 Filed April 22, 1959 J. S. MELLOTT ETAL SAWMILL LOG TURNER3 Sheets-Sheet 1 INVENTORS JOHN s'. MELLOTT HAYES R. MELLOTT ATTORNEYSAug. 9, 1960 J. 5. MELLOTT EI'AL 2,948,313

SAWMILL LOG TURNER 3 Sheets-Sheet 2 Filed April 22. 1959 INVENTORS JOHNS. MELLOTT HAYES R. MELLOTT ATTORNEYS Aug. 9, 1960 5, MELLOTT ETAL2,948,313

SAWMILL LOG TURNER Filed April 22, 1959 3 Sheets-Sheet 3 INVENTORS JOHNS. MELLOTT y HAYES R. MELLOTT MJAMK ATTORNEYS.

United States Patent SAWMILL LOG TURNER John S. Mellott, RR. 6,Hagerstown, Md., and Hayes R. Mellott, RR. 1, Mercersburg, Pa.

Filed Apr. 22, 1959, Ser. No. 808,136 8 Claims. (Cl. 143-103) Thisinvention relates to improvements in sawmill 10g turner assemblies.

It is a primary object of the invention to provide a sawmill log turneroperable to turn logs of diflerent diameters through an angle ofsubstantially 180 degrees.

It is another object of the invention to provide a sawmill log turnerwhich is operable to positively rotate a log through an angle ofsubstantially 180 degrees in which the log engaging parts of theassembly are not confined to movement in a fixed path to compensate forvarying dimensions or irregularities of the log.

Still another object of the invention is to provide a sawmill log turnerhaving a log engaging prong which is maintained in engagement with thelog by the weight of the log itself.

Still another object of the invention is to provide a sawmill log turnerin which the motion of the log turning parts is controlled to disengagethe log engaging parts from the log at the completion of the turningoperation.

Other objects and features of the invention will become apparent byreference to the following specification taken in conjunction with theaccompanying drawings.

In the drawings:

Fig. 1 is a side elevational view of an exemplary embodiment of theinvention;

Fig. 2 is a plan view of the log turner of Fig. 1;

Fig. 3 is a partial side elevational view of the assembly of Fig. 1taken from the opposite side of the assemb v;

Fig. 4 is a side elevational view of the assembly taken from the sameside as Fig. 3 showing in full and dotted lines movements of the variousparts during the initial portion of the retracting stroke with certainparts broken away;.

Fig. 5 (Sheet 1) is a cross sectional view taken on line 5-5 of Fig. 1shovw'ng details of the. extensible link assembly;

Fig. 6 is a general side elevational view of the assembly showing therelationship between the turning structure and a log at the start of theturning operation;

Fig. 7 is a view similar to Fig. 6 showing a later stage of the turningoperation; and

Fig. '8 is a view similar to Figs. 6 and 7 showing still another stageof the turning operation.

The log turner shown in the drawings is especially designed for use insawmills to rotate a log L about its longitudinal axis through an angleof 180 degrees.

The log turner includes a fixed frame designated generally 10 which inthe particular construction shown includes a pair of rigid side channels:12 braced at either end as by cross pieces 14 welded to the sidechannels.

A shaft 16 is supported between side channels 12 to rotatably support asleeve 18, the sleeve 18 being supported for rotation about a horizontalaxis. A crank 20 is rigidly welded to sleeve 18 for rotation with thesleeve. A hydraulic motor 22 of conventional construction has itscylinder or casing pivotally connected to fixed frame 10 as by a bracketassembly 24. Piston rod ice 26 of motor 22 is pivotally connected tocrank 20 as at 28. Movement of the piston of motor 22 within thecylinder is employed in a conventional manner to retate crank 20, andhence sleeve 18 about the axis of shaft 16.

At each end of sleeve 18, rigid crank arms 30 are rigidly connected tothe sleeve for rotation with the sleeve. At the distal end of each crank30, a pivot 32 connects a rigid arm 36 to each crank, the arms beingrotatable relative to the cranks about a common axis parallel to theaxis of sleeve 18.

Arms 36 are rigidly interconnected into a rigid framework by a crossframe member 38 fixedly secured to each arm near its upper end.

A pair of frame members 40 are welded at one end to cross piece 38 andproject from the cross piece to support at their outer end a logengaging member 42. Log engaging member 42 is supported for freerotation between frame members 40 upon a shaft 44 which is receivedwithin a hub upon the member. Member 42 includes a log engaging point orprong 46, a counterbalancing weight 48 and a log engaging abutmentsurface 50 located on the opposite side of the axis of shaft 44 fromprong 46. Counterbalancing weight 48 is located so that prong 46 isnormally maintained in the relationship to its axis shown in Fig.1namely below and to one side of the axis.

Since the arm assembly which includes sleeve 34, arms 36, etc., isfreely rotatable upon shaft 32, it is necessary to provide structure forcontrolling the movement of the arm assembly about its pivotal axis. Atone side of the frame assembly a lug 5 2 (Fig. 1) is mounted upon sidechannel 12 to project upwardly about the channel. An elongated slot 54receives a pivot pin 56 which rotatably supports one end of anextensible link assembly designated generally 58 upon fixed frame 10.

As best seen in Fig. 5, link assembly 58 includes a first link section60 which is pivotally supported at one end upon pin 56. A second linksection 62 is pivotally supported at one end upon the adjacent arm 36 asby a pivot pin 64. A plurality of guide brackets 66 are fixed to link 62and project outwardly from one side of the member to define openingswithin which link 60 is slideably received. Thus, links 60 and 62 areconnected to each other so that only sliding linear relative movementmay take place between the links.

A stop 68 (Fig. 5) is welded to link section 60, and when engaged by theright-hand end of link section 62 defines a minimum length of theextensible link assembly. This minimum length in turn defines a minimumangulardisplacement between crank 30 and arm- 36.

Since prong 46 is driven into the log during the turning operation, itis desirable, when disengaging member 42 from the log to cause themember to move in a direction in which prong 46 is directly withdrawnfrom the log. This action is accomplished by the ratchet structure shownin Figs. 3 and 4 which includes a lug 70 welded upon side channel 12 ata location within the arc traversed by crank 30. Lug 70 projectsupwardly a substantial distance from side channel 1.2 to support a pivotpin 72 which in turn supports a link 74 for pivotal movement upon lug.70. The outer end of link 74 is slideably received within a guideassembly 76 mounted upon a ratchet link 78. Ratchet link 78 is pivotallyconnected to arm 36 as at 80. The coupling between link 74 andratchetlink 78 permits only linear sliding movement of one of the linksrelative to the other in the same fashion as the relative movementbetween sections '60 and 62 of the extensible link assembly.

Ratchet link 78 is formed with a series of ratchet teeth 82. The pawlportion of the ratchet assembly includes an arm 84 pivotally supportedfrom side channel -12 as at 86 and -normally biased in a directiontoward ratchet link 78 by means of a tension spring 88 connected betweenthe lower end of arm 84 and a lug 9! fixed to side chan- :nelzlZ.JAsrthe'assembl-y approaches the fully =--actuated posi--tioncshowminiFig "4, :36 travelsto.itsggreatestangular idisplacement:away irom'rcrank :30. P-awl teeth :92 atthe end of arm 84 is biasedagainst the ratchet teeth 82-.-on link 78 :dun'ng ;tl1e final portionaof "the turning moverment, :and mas :the angular .displacementof arm.36 from :30 increases, :fin'ger 92 ssuccessively 1 engages teethfizupawlttooth 92*moving;downwardly along teeth-.82 as the angulardisplacement =of .:arms 36 and crank 30 increase.

'WhentcrankfiO issrotatedta-sclockwise direction in iFig. 4 to :returnthe assembly to ;its rest 'position, the geometric relationship of arm36 and:log:engagingmemm to -pivotalaxis 32 isz'such that :arm '36 wouldbe gravitationally biased in acounterclockwise direction :as -vieWed inFig. 4. Thisaction woulditendito cause tooth "M' -to'bindwith log L.Theratchetstructure is operable 't'luri'ng the initial portion of.retraction of the assembly "to maintainthe maximumangular-displacementachieved between crank 30 and arm 36 during theupper portion of the stroke. Thus, during the initial retraction, prong46 moves along an are centered :at the axis of shaft -16.

When the assembly has been retractedrto the lposition -shown in broken'line'in Fig. 4, :the tension exerted by spring 88-is substantiallyreduced, hence theforce urging pawl tooth 92 against teeth 82 isdiminishedand further elokwise rotation of crank 30 disengagestooth82from -pawltooth 92, thus permitting arm 36 to rotate counterclockwisetoward crank 30, the *rate of-movement being --'restricte'd beoause ofthe straight linesliding relationship permitted byguides 66 onextensible link-assembly -58 Operation of the-log'turner may best-beappreciated by reference "to Figs. 6 through 8 of the drawings. As shownin these figures,the-log turner will be mounted in =fixed'rel ationshipto a conventional log supporting structure which-includes asupport-platform P, afixed side stop 81 and a movable stop S2 which ismounted for movement in a well-known fashion toward and away *f romsidestop S1. The log 'L is supported .upon the platform? between the twoside stops, side stop S2 being 'adjus ted' horizontally 'so that the logY is engaged between *the s-ide stops. The log is maintained in-thisposit-ion 'while being -sawed, the saw passing through-the log to make avertical cut in approximately the plane indicated at c-C in'Fig/G.

As'best seen in Fig. 6, the log turning assembly is 10- cated below andto'one side of the log which 'is tobe turned. The pivotal axes definedbyshafts 1'5 and pivots 32 'and 44 extendparallel to'thelongitu'dinalaxis of the log L. The turning assembly is locatedsomewhat beyond theends of thelog supports and the end of the log isprojectedbeyond the supports in order that the moving parts of theturningassembly will not engage'thevarious supports P, S1 and S2.Preferably, the turning assembly is located with respect vto supports S1and P so that the normal path of prong pivot 44 passes platform "P'inapproximate alignment with the intersection of the'platformand stopSl.

When motor 22 is actuated, by conventional means, to extend pistonrod 26from the motor, crank 30 is driven in rotation in 'a clockwise directionfrom the position shown-in Fig. 6 to'the position-shown in Fig. 7.The'log engaging'p arts of the assembly'thus initially engage the log inthe lower left quadrant of the log as viewed in Fig. 7. Abutment portion'50 tis'the first portion of the assembly to engage the log and as thestrong pivot point 44 is driven upwardly along the path, assembly 42 isrotated to drive;prong-46 upwardlyinto engagement with the'log. Prong 46will "engage the log approximately directly below-"the central axisofthelog.

During movement of the assembly from its lower or rest position intoengagement with the log, arm 36 is gravitationally biased to maintainthe angular displacement between arm 36 and crank 30 at a minimum, thusmaintaining extensible link assembly 58 at its minimum length. After thelog is engaged by the assembly, the reaction of the log uponzanmfifitends to reduce this angular displacement, however stop .68.,preventsthis action.

With prong '46 engaged "in the log, the normal direction of :rn'ovementof -,pivot- 44 "would be upwardly -and-.to the right.Sincethealog:iszheldsagainst' horizontal movement to the right by stop.82 and gravitationally held against upward movement, further rotationof crank 30 forces prong pivot 44-to' 'be driven in a circular pathconcentric with the axis of the log. In order to accommodate thisrevised motion of prong pivot 44, the angular displacement between crank30 and arm 36 increases, the increasing angular displacement being;,permitted by extension of extensible link 58. There is:substantiallyno resistance exerted 'by link 58 to =1novement tending toextend or 'elongate the link assembly. :Sincerprong-=46.is forciblyengaged with 1 the log, movement v of 'prongpivot w4 4 along theconcentric circulanpath.causeswthezzlog to rotate :in .a clockwisedirection: about its "longitudinal axis. Since :the normal movement .of:prong :pivot 44 :upon clockwise rotation .of crank 30 is primarily 'ito=i'the;ri-g'ht -.as viewed infigs. 6*through 8, tprong 46stays'inengagement with a the llog'a's the pivot is driven upwardly:above the .axis :ofitheilog.

"As pronggpivot 4:4 approaches .arpositiondirectlyeabove the .axis .ofzthelog, pawl tooth ."fl2mhecomes :engaged -with teeth 8-2 of theratchet assembly (Fig.4 ZIihesmaximum .angular displacement:betweenzcrankzfitltand arm 36 occurs as .prong pivot :44 passes above.the .lOgitO ra .loca .tion beyond :the;,axis of the 10g. :In order'tomaintain .engagement withithetlog as .prongzpivot 44 moveszto-theposition .of Fig. '8, the angular displacement between rotten-k 31i. andarm 536 would :have :to I decrease, -;however, the engagement betweenpawl tooth .92 and. ratchet I teeth 82 prevents such a decrease inangular displacement: and hence :as prong :pivot =441approaches atheposition shown in Fig. 8, continued rotation ofzcrank330ina clockwisedirection beginszto drive prong pivot 44vaway fromthelog. Continueddlockwise: rotationot .crank30 disengagestprong 46zfromcthelog asthetprong-ireaches1a ,position approximately directly above the axis ofthe log. Since the .prong -46ihascbeen'i inLengagement-With the logthrough ap- .proximately .1 80 degrees, the log has :tumed throughapproximately 7180 .degrees.

Dur ingthe retracting movement :of the assembly 'by reversal of thestroke of motor 22, crank 30 is rotated in a-counterclockwise-direction.Pawl tooth"92lremains in engagement with the ratchetuntil crank 310 is--lowered beyond the position indicated approximately "in dotted linesin Fig. 4. At this time, ratchet-arm 84 I is no longer forcibly biasedtowardarm 78 by spring fis and -tooth 92 becomes disengaged from ratchetteeth 82. Arm 36 -is I then gravitationally =urged'to pivot toward arm30,-thus returning the parts to the position shown in Fig.1 as crank '30reaches "its lower rest position.

While a particular enibodimedt'has' been descfibed, it Will be apparentto thoseskilledintheart thatthe disclosed embodiment may "be modified.Therefore, the foregoing descriptioniisato beconsidered exemplary"rather than limiting "and the true scope "of the "invention isthatdefined in the "following -'claims.

-We claim:

"1. A sawmill log turner comprising a fixe'd 'frame, a crankassemblymounted in said frame forpivotal movementabout a horizontal first axis,-means on -sa-id frame for 'rotating said crank assembly between 1 arest positionwherein sa-id crank assembly iS incIined belOW thehorizontal and an actuated-position wherein said #crank assembly is,inclined "above the horizontal, an arm nssembly pivotally mounted attheouter end of said crank tion toward said first axis, a log engagingmember ineluding a prong mounted at the upper end of said am assemblyfor rotation about a third axis parallel to said first axis, meanscounterbalancing said log engaging member to normally maintain saidprong facing away from said arm assembly at a location below saidthirdaxis, a log engaging abutment portion on said log engaging normallylocated above said third axis, said surface and said prong facing awayfrom said arm assembly to operatively engage a log supported in the pathof movement of said member with the longitudinal axis of the logextending parallel to said first axis, said arm assembly being normallygravitationally biased to rotate about said second axis in a directiontoward said crank assembly, and extensible link means pivotally coupledbetween said frame and said arm assembly for controlling the angularrelationship between said arm assembly and said crank assembly duringmovement of said crank assembly between said rest and said actuatedpositions.

2. A sawmill log turner comprising a fixed frame, a crank assemblysupported at one end on said frame for pivotal movement about ahorizontal first axis, means for driving said crank assembly in pivotalmovement about said first axis between normal rest position and anelevated position wherein said crank assembly is inclined upwardly fromsaid axis, an arm assembly supported at the opposite end of said crankassembly for pivotal movement relative to said crank assembly about asecond axis parallel to said first axis, said arm assembly beinginclined upwardly from said second axis and gravitationally urged towarda minimum angular displacement from said crank assembly, freelyextensible link means connected between said frame and said arm assemblyat a location intermediate the ends of said arm assembly, means on saidlink means for establishing a minimum length of said link means tothereby establish a minimum angular displacement between said crankassembly and said arm assembly, log engaging means mounted at the upperend of said arm assembly facing outwardly from said assembly tooperatively engage a log supported in the path of movement of said logengaging means with the axis of said log extending parallel to saidfirst axis, and means operable when said crank is adjacent said elevatedposition for preventing pivotal movement of said arm assembly about saidsecond axis toward said crank assembly.

3. A sawmill log turner as defined in claim 2 wherein said meansoperable when said crank is adjacent said elevated position comprises asecond extensible link means connected between said frame and said armassembly, ratchet means on said second extensible link means, and pawlmeans on said frame engageable with said ratchet means while said crankassembly is adjacent said elevated position to maintain said secondextensible link means at the maximum extension of said second extensiblelink means incurred during movement of said crank assembly adjacent saidelevated position, said pawl means being disengageable from said ratchetupon movement of said crank assembly below a selected angle above thehorizontal.

4. A sawmill log turner comprising a fixed frame, a crank assemblysupported at one end on said frame for pivotal movement about ahorizontal first axis, means for driving said crank assembly in pivotalmovement about said first axis between a normal rest position and anelevated position wherein said crank assembly is inclined upwardly fromsaid first axis, a pair of rigidly interconnected horizontally spacedparallel arms. mounted at one end on said crank assembly for pivotalmovement about a second axis parallel to said first axis, said armsbeing inclined upwardly from said second axis and gravitationally biasedtoward a minimum angular displacement from said crank assembly, logengaging means pivotally supported at the upper endof said arms forrotation about a third axis parallel to said first axis, said log en'-gaging means including a prong and a log engaging abutment facingoutwardly from said arms to operatively engage the log supported in thepath of movement of said log engaging means with the longitudinal axisof said log extending parallel to said first axis, freely extensiblelink means pivotally connected at one end to said frame adjacent saidfirst axis and pivotally connected at the opposite end to one of saidarms, means on said link means defining a length of said link means tothereby establish a minimum angular displacement between said arms andsaid crank assembly, a second extensible link means pivotally connectedat one end to said frame adjacent said first axis and pivotallyconnected at the opposite end to the other of said arms, ratchet meanson said second extensible link means, pawl means on said frameengageable with said ratchet means when said crank assembly is adjacentsaid elevated position to maintain said second extensible link means atthe maximum extension incurred during movement of said crank assemblyadjacent said elevated position, said pawl means being disengageablefrom said ratchet means upon movement of said crank assembly toward saidnormal rest position.

5 For use in combination with a sawmill having means for supporting alog with the axis of the log extending in a horizontal direction; a logturner assembly comprising a vertically inclined arm, a log engagingmember mounted upon a pivot at the upper end of said arm for pivotalmovement relative to said arm about a first axis extending parallel tothe axis of a log supported on the sawmill, a prong and an abutmentsurface on said log engaging member facing outwardly of said first axisfrom said arm and normally disposed in a rest position wherein saidprong is located below said first axis and said abutment surface islocated above said first axis, pivotal support means at the lower end ofsaid arm supporting said arm for pivotal movement about a second axisparallel to said first axis, and means for driving said pivotal supportmeans from a lower rest position to an elevated actuated position todrive said log engaging member along a path of movement wherein saidpivot is driven toward the axis of said log until said prong and saidabutment surface are engaged with the log and is subsequently drivenupwardly around the axis of the log with said prong fixedly engaged withthe log until the log has been rotated about its axis through an angleof approximately 6. A sawmill log turner comprising a frame, a crankpivotally mounted at one end on said frame for pivotal movement about ahorizontal first axis, means for rotating said crank about said firstaxis between a normal rest position wherein said crank is inclineddownwardly from said first axis and an actuated position wherein saidcrank is inclined upwardly from said first axis, said rest position andsaid actuated position of said crank being located on the same side of avertical plane passing through said first axis, an arm pivotallyconnected at one end to the other end of said crank for pivotal movementabout a second axis parallel to said first axis, said arm being inclinedupwardly from said second axis toward said plane whereby said arm isgravitationally biased about said second axis toward said crank, meansfor establishing a minimum angular displacement between said arm andsaid crank about said second axis, a log engaging member mounted uponthe upper end of said arm for pivotal movement about a third axisparallel to said first axis, said member including a prong, a logabutment surface angularly displaced about said third axis from saidprong, and a counterweight for normally locating said surface and saidprong facing away from said arm with said prong located below saidsurface to operatively engage a log supported in the path of movement ofsaid member with the axis of said log extending parallel to said firstaxis, and means operable when said crank is located ad.

17 'jacent =sa'ii1 actuated *pos'ition -forzpreventing movement of saidarm a'rbout seiid second -a-xis in a direet'ion toward 'sz'iiderank. v

*7. A=s-awmill log turneras defined in elaim 6'wherein said means forestablishing a minimum angular displace- *ment'ofsa-i'd arm'from-saidcrank-assembly comprises -:ex- 'tensilile iinkmeans --ineh1 din-g afirst link pivot-ally connected 'to said frame and a secondlink'pivotall y connected to-said "arm, means connecting said linkstoeach "other'to'confine relativemovement of said links 'to linearsliding movement and-stop means on one 'link engageable 'withtheotheriink-to define a minimum length of saidlink'means.

8. A sawmill 10g-tumer as definedin claim 7 wherein lkeferences Cited inthe file of thispatent -UNITED STATES PATENTS Re. 12,353 -Wi1kin May 30,1905 640,503 Thomas 1 Jan. 2, 1900 1,191,609 Payne July 18, 191612,586,483 Ross ..Feb. 19, 1952

